Micro-electromechanical system package having movable platform

ABSTRACT

A MEMS package including a fixed frame, a moveable platform and elastic restoring members is provided. The moveable platform is moved with respect to the fixed frame. The elastic restoring members are connected between the fixed frame and the moveable platform, and used to restore the moved moveable platform to an original position.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 17/091,062, filed on Nov. 6, 2020, which is a continuationapplication of U.S. application Ser. No. 16/783,627, filed on Feb. 6,2020, which is a continuation application of U.S. application Ser. No.16/448,612, filed on Jun. 21, 2019, which is a divisional application ofU.S. application Ser. No. 15/891,975, filed on Feb. 8, 2018, the fulldisclosures of which are incorporated herein by reference.

BACKGROUND 1. Field of the Disclosure

This disclosure generally relates to a sensor package, moreparticularly, to an encapsulation with a movable sensor that arranges asensor on a movable platform of a MEMS actuator and a manufacturingmethod thereof.

2. Description of the Related Art

The micro-electromechanical system (MEMS) is a micro-mechanicalstructure formed by etching a silicon wafer, and can be used as a MEMSactuator which converts electrical signals to mechanical motion forcontrolling tiny movement.

In the image acquiring device having an auto-focus (AF) function oroptical image stabilization (OIS) function, the MEMS actuator can beused to implement the exact adjustment of the focus length and samplingposition.

SUMMARY

The present disclosure provides an encapsulation having a movable sensorand a manufacturing method thereof that have a sensor chip arranged onthe elastic structure which has functions of restoring position andtransmitting electrical signals.

The present disclosure provides a MEMS package including a fixed frame,a moveable platform and multiple elastic restoring members. The moveableplatform is configured to be moved with respect to the fixed frame alongat least one direction and having a rectangular shape, wherein themoveable platform comprises a plurality of comb electrodes at twoopposite edges of the rectangular shape of the moveable platform. Themultiple elastic restoring members are formed between the fixed frameand another two opposite edges, different from the two opposite edges,of the rectangular shape of the moveable platform, and configured torestore a position of the moved moveable platform.

The present disclosure further provides a MEMS package including a fixedframe, a moveable platform and four elastic restoring members. The fixedframe has a rectangular inner edge. The moveable platform is configuredto be moved with respect to the fixed frame along two directions. Thefour elastic restoring members are straightly connected between thefixed frame and the moveable platform, and configured to restore aposition of the moved moveable platform, wherein one end of each of thefour elastic restoring members is arranged at one of four corners of therectangular inner edge of the fixed frame.

The present disclosure further provides a MEMS package including a fixedframe, a moveable platform and at least one elastic restoring member.The moveable platform is configured to be moved with respect to thefixed frame along at least one direction. Each elastic restoring memberis formed as a straight line between the fixed frame and the moveableplatform, and configured to restore a position of the moved moveableplatform.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages, and novel features of the present disclosurewill become more apparent from the following detailed description whentaken in conjunction with the accompanying drawings.

FIG. 1 is a top view of a sensor package according to one embodiment ofthe present disclosure.

FIG. 2 is a top view of a sensor package according to another embodimentof the present disclosure.

FIG. 3 is a top view of a sensor package according to an alternativeembodiment of the present disclosure.

FIG. 4 is a side view of a sensor package according to an alternativeembodiment of the present disclosure.

FIGS. 5 a-5 f are schematic diagrams of the manufacturing of a sensorpackage according to a first embodiment of the present disclosure.

FIGS. 6 a-6 h are schematic diagrams of the manufacturing of a sensorpackage according to a second embodiment of the present disclosure.

FIG. 7 is a flow chart of a manufacturing method of a sensor packageaccording to a first embodiment of the present disclosure.

FIG. 8 is a flow chart of a manufacturing method of a sensor packageaccording to a second embodiment of the present disclosure.

FIG. 9 is a top view of a sensor package according to an alternativeembodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENT

It should be noted that, wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

Referring to FIG. 1 , it is a top view of a sensor package 10 accordingto one embodiment of the present disclosure. The sensor package 10 is,for example, an image sensor package. The sensor package 10 includes amicro-electromechanical system (MEMS) actuator used to change theone-dimensional or two-dimensional position of a carried optoelectroniccomponent. The optoelectronic component is a component independent fromthe MEMS actuator, and is arranged on the MEMS actuator via elasticrestoring members after the MEMS actuator is manufactured. Theoptoelectronic component transmits detected data via the elasticrestoring members.

The MEMS actuator includes a fixed frame 11 and a moveable platform 13that are micro-electromechanical structures formed by processing asilicon wafer (illustrated by an example below) using thephotolithography or etching process. In the processed silicon wafer, themoveable platform 13 is separated from the fixed frame 11 (onlyconnected by elastic restoring members as mentioned below) such that themoveable platform 13 can move with respect to the fixed frame 11.

The fixed frame 11 has a plurality of first comb electrodes 111 (only afew being shown), and the moveable platform 13 has a plurality of secondcomb electrodes 131 (only a few being shown). As shown in FIG. 1 , thefirst comb electrodes 111 are arranged at two opposite inner sides ofthe fixed frame 11, and the second comb electrodes 131 are arranged attwo opposite edges of the moveable platform 13. The first combelectrodes 111 and the second comb electrodes 131 are used to generateelectrostatic force to cause the moveable platform 13 to have movementalong at least one direction with respect to the fixed frame 11. Asshown in FIG. 1 , each of the first comb electrodes 111 is arrangedbetween two second comb electrodes 131, and each of the second combelectrodes 131 (in addition to the most outside second comb electrodes)is arranged between two first comb electrodes 111. By applying voltageson the first comb electrodes 111 and the second comb electrodes 131,attractive force or repulsive force is generated (depending on thevoltage polarity being applied) to move the moveable platform 13.

The elastic restoring members 15 are formed by a patterned conductivemetal layer such as Aluminum, Nickel, Gold or a combination thereof. Theelastic restoring members 15 are the structure additionally formed on asilicon wafer (e.g., using deposition technology), but not formed byetching the silicon wafer. The elastic restoring members 15 areconnected between the fixed frame 11 and the moveable platform 13, andused to restore the moved moveable platform 13 to an original position.

For example in FIG. 1 , the moveable platform 13 is shown to have arectangular shape, and the elastic restoring members 15 are formedbetween two opposite edges (shown as left and right edges) of therectangular shape and the fixed frame 11. For example, one end of theelastic restoring members 15 is arranged on a surface of the fixed frame11, and the other end thereof is arranged on a surface of the moveableplatform 13. When the first comb electrodes 111 and the second combelectrodes 131 form electrostatic force along an up-down direction, themoveable platform 13 is moved along the up direction or down direction.The elastic restoring members 15 generate restoring force opposite tothe electrostatic force.

The sensor chip 17 is, for example, a CMOS image sensor chip or CCDimage sensor chip, and is disposed on the moveable platform 13. Thesensor chip 17 transmits detected data, e.g., image data or datadetected by other optoelectronic components, via the elastic restoringmembers 15. For the electrical connection, the sensor chip 17 includessolder balls or contact pads, e.g., multiple solder balls or contactpads under a bottom surface of the sensor chip 17 as electricalconnection points. The sensor chip 17 is electrically connected to theelastic restoring members 15 via the solder balls or contact pads.

FIGS. 2 and 3 are top views of a sensor package according to otherembodiments of the present disclosure. The sensor packages 10′ and 10″also include a fixed frame 11, a moveable platform 13, elastic restoringmembers 15 and a sensor chip 17. The difference from FIG. 1 is that thefixed frame 11 and the moveable platform 13 in FIGS. 2 and 3 areconnected by elastic restoring members 15 arranged in a different way toallow the moveable platform 13 to move in the one-dimensional directionor two-dimensional directions with respect to the fixed frame 11.

For example in FIG. 2 , more elastic restoring members 15 are arrangedat left and right edges of the rectangular moveable platform 13 togenerate larger restoring force. It is appreciated that the amount ofrestoring force is determined not only according to a number of theelastic restoring members 15, but also according to a size and thicknessof the elastic restoring members 15. The size, thickness and/or numberof the elastic restoring members 15 are arranged during manufacturingaccording to the electrostatic force generated by the first combelectrodes 111 and the second comb electrodes 131. The amount ofelectrostatic force is determined, for example, according to a number,size, pitch and applied voltages of the first comb electrodes 111 andthe second comb electrodes 131.

For example in FIG. 3 , the elastic restoring members 15 are arrangedbetween four corners of the moveable platform 13 and the fixed frame 11to generate restoring force along two directions (e.g., up-downdirection and left-right direction). Meanwhile, to generateelectrostatic force in two directions, the first comb electrodes 111 andthe second comb electrodes 131 are further arranged at two oppositesides along the left-right direction.

In the present disclosure, a number and position of the comb electrodesets 111 and 131 are not particularly limited but determined accordingto actual applications as long as the restoring force generated by theelastic restoring members 15 can balance the electrostatic forcegenerated by the comb electrode sets 111 and 131.

It is appreciated that positions of the elastic restoring members 15 arearranged corresponding to electrical contacts (e.g., solder balls orcontact pads) of the sensor chip 17 to allow the sensor chip 17 to bedirectly disposed on the moveable platform 13 and electrically combinedto the elastic restoring members 15 via the electrical contacts. Inaddition, as the elastic restoring members 15 are further used totransmit detected data as well as the fixed frame 11 and the moveableplatform 13 are applied with voltages to generate electrostatic force,an electrical insulation layer 16 is further formed between the moveableplatform 13 and the elastic restoring members 15 and between the fixedframe 11 and the elastic restoring members 15, as shown in FIG. 4 , toprevent from degrading the signal quality.

FIG. 4 is a side view of a sensor package according to anotherembodiment of the present disclosure, wherein the sensor chip 17transmits electrical signals (e.g., control signals and/or detected dataof the sensor chip 17) not only via the elastic restoring members 15 butalso via at least one bonding wire 19 connected between the sensor chip17 and the fixed frame 11. For example, the fixed frame 11 further hasat least one electrical contact pad thereon, and at least one bondingwire is connected between the solder balls 18 and the at least oneelectrical contact pad on the fixed frame 11 using wire bondingtechnology. In FIG. 4 , the fixed frame 11 includes a first siliconlayer 111, a second silicon layer 13 and an oxide insulating layer 12between the first silicon layer 111 and the second silicon layer 13.

Referring to FIGS. 5 a-5 f and 7, a manufacturing method of a sensorpackage according to a first embodiment of the present disclosure isillustrated below. The manufacturing method includes the steps of:providing a silicon on insulator (SOI) wafer having a first siliconlayer, an oxide insulating layer and a second silicon layer (Step S71);forming a patterned metal layer on the first silicon layer (Step S72);etching the first silicon layer to form a platform region, a fixed frameand a groove between the platform region and the fixed frame (Step S73);etching the second silicon layer to form an exposed region correspondingto the platform region and the groove (Step S74); etching the oxideinsulating layer within the exposed region to release the platformregion to form a movable platform (Step S75); and arranging a sensorchip on the patterned metal layer (Step S76).

Step S71: The SOI wafer has a first silicon layer 51, a second siliconlayer 53 and an oxide insulating layer 52 sandwiched therebetween, asshown in FIG. 5 a . The SOI wafer is selected from commercial availableSOI wafers or a self-manufactured SOI wafer without particularlimitations. For example, the first silicon layer 51 is a silicon waferused as a device layer and having a thickness of about 10-20micrometers, and the second silicon layer 53 is a silicon wafer used asa handle layer and having a thickness of about 300-400 micrometers. Theoxide insulating layer 52 is used as an etch stop layer.

Step S72: Next, a patterned metal layer 55 having a predeterminedpattern is formed on the first silicon layer 51, as shown in FIG. 5 b ,used as elastic restoring members for the MEMS actuator. Thepredetermined pattern is previously arranged according to positions ofthe solder balls 58 or contact pads of the sensor chip 57 to be disposedlater (e.g., referring to FIG. 5 f ). The patterned metal layer 55 isformed, for example, by photolithography.

In addition, to improve signal quality, before the metal layer isdeposited, an electrical insulation layer 16 (as shown in FIG. 4 ) isformed on the first silicon layer 51 firstly to electrically insulatethe patterned metal layer 55 from the first silicon layer 51.

Step S73: Next, the first silicon layer 51 is etched by the vapor-phaseetching or wet etching to form a platform region 513, a fixed frame 411and a groove 515 between the platform region 513 and the fixed frame 511as shown in FIG. 5 c . The arrangement after the etching is selectedfrom one of FIGS. 1-3 according to actual applications. With theexistence of the oxide insulating layer 52, the etching 51 on the firstsilicon layer 51 stops while reaching the oxide insulating layer 52.After the etching of this step, the patterned metal layer 55 crosses thegroove 515 and connects between the platform region 513 and the fixedframe 511 to be used as the elastic restoring member. The platformregion 513 connects to the fixed frame 511 through the oxide insulatinglayer 511.

Step S74: To release the platform region 513 in the following steps, thesecond silicon layer 53 is etched (e.g., using dry/wet etching) to forman exposed region 531 corresponding to the platform region 513 and thegroove 515 to expose a part of the oxide insulating layer 52. Theetching also stops while reaching the oxide insulating layer 52, asshown in FIG. 5 d.

It is appreciated that the protection layer is formed during the processof etching the first silicon layer 51 and the second silicon layer 53 inorder to form a predetermined structure in the first silicon layer 51and the second silicon layer 53. The first silicon layer 51 and thesecond silicon layer 53 are etched using the etching technology formanufacturing the MEMS, and thus details thereof are not describedherein.

In addition, the Step S73 is not limited to be performed before the StepS74. It is possible to etch the second silicon layer 53 at first, andthen the first silicon layer 51 is etched as long as the exposed oxideinsulating layer 52 corresponds to the platform region 513 and thegroove 515.

Step S75: Next, the oxide insulating layer 52 within the exposed region531 is etched to release the platform region 513 to form a moveableplatform, as shown in FIG. 5 e . Due to different etching selectionratio, the etching performed on the oxide insulating layer 52 does notetch the first silicon layer 51 and the second silicon layer 53, or viceversa. After this step is finished, the platform region 513 connects tothe fixed frame 511 only via the patterned metal layer 55, and the otherpart of the platform region 513 is totally separated from the fixedframe 511.

Step S76: Finally, a predetermined sensor chip 57 is disposed on thepatterned metal layer 55. The sensor chip 57, for example, has solderballs 58 previously arranged on a bottom surface thereof. After thesolder balls 58 are combined to the patterned metal layer 55 using ahigh temperature technology, the sensor package of the presentdisclosure is accomplished, as shown in FIG. 5 f . The high temperaturebeing used is determined according to the material of solder balls 58and the temperature tolerance of the sensor chip 57.

In addition, if bonding wires are required to be arranged in addition tothe patterned metal layer 55, the wire bonding is performed after theStep S76 or before the moveable platform 513 is released in the Step S75to form at least one bonding wire between the sensor chip 57 and thefixed frame 511, as shown in FIG. 4 . For example, at least oneelectrical contact pad is further formed on the fixed frame 511 and theplatform region 513 to bond with the bonding wire. Accordingly, a partof solder balls 58 of the sensor chip 57 are arranged on the patternedmetal layer 55, and the other part of solder balls 58 are arranged onthe electrical contact pad of the platform region 513 to electricallyconnect with the bonding wire.

In the sensor package manufactured by FIGS. 5 a-5 f , the fixed frame 11includes a first silicon layer 511, a second silicon layer 53 and anoxide insulating layer 52 between the first silicon layer 511 and thesecond silicon layer 53.

Referring to FIGS. 6 a-6 h and 8, a manufacturing method of a sensorpackage according to a second embodiment of the present disclosure isillustrated below. The manufacturing method includes the steps of:providing a first silicon layer having a first surface and a secondsurface (Step S81); forming a patterned metal layer on the first surfaceof the first silicon layer (Step S82); bonding a second silicon layer tothe first surface of the first silicon layer (Step S83); thinning thefirst silicon layer (Step S84); etching the thinned first silicon layerto form a movable platform and a fixed frame (Step S85); bonding a thirdsilicon layer to the thinned surface of the first silicon layer (StepS86); removing the second silicon layer to expose the moveable platformand the patterned metal layer (Step S87); and arranging a sensor chip onthe patterned metal layer (Step S88).

Step S81: Instead of using an SOI wafer, a first silicon layer 61 isdirectly used to start the manufacturing. The first silicon layer 61 hasa first surface 61S1 and a second surface 61S2 opposite to each other.

Step S82: A metal layer is deposited on the first surface 61S1 of thefirst silicon layer 61, as shown in FIG. 6 a . The metal layer is formedby conductive metal such as Aluminum, Nickle, Gold or a combinationthereof. Then, the patterned metal layer 65 is formed usingphotolithography, as shown in FIG. 6 b . As mentioned above, a patternof the patterned metal layer 65 is determined previously according tothe arrangement of the solder balls or contact pads of the sensor chipbeing used.

In addition, to allow the patterned metal layer 65 to have goodinsulation from the first silicon layer 61, an electrical insulationlayer 16, as shown in FIG. 4 , is firstly formed on the first surface61S1 of the first silicon layer 61 before the patterned metal layer 65is formed to electrically isolate the first silicon layer 61 and thepatterned metal layer 65.

Step S83: Next, a second silicon layer 63 having an accommodation spaceis used to bond with the first surface 61S1 (with the part whose metallayer and electrical insulation layer 16, if there is, being removed) ofthe first silicon layer 61, and the patterned metal layer 65 isaccommodated in the accommodation space. For example, FIG. 6 c showsthat the second silicon layer 63 is bonded to the first surface 61S1 ofthe first silicon layer 61 only with the fringe region thereof, but notlimited thereto. The bonded region is determined according to a positionof the moveable platform being arranged. For example, the second siliconlayer 63 has walls extending upward from edges thereof such that thecentral area is lower than the fringe area. The first silicon layer 61and the second silicon layer 63 are bonded using conventional waferbonding technology without particular limitations.

Step S84: Next, the first silicon layer 61 is thinned to form a thinnedfirst silicon layer 61′ having a thickness of about 10-20 micrometers,as shown in FIG. 6 d . The thinning is performed by grinding or etchingthe second surface 61S2. In some embodiments, if the first silicon layer61 is thin enough, the thinning step is omitted.

Step S85: Next, the thinned first silicon layer 61′ is etched to form amoveable platform 613 and a fixed frame 611, as shown in FIG. 6 e . Thearrangement of the moveable platform 613 and the fixed frame 611 byetching the first silicon layer 61 is selected from one of FIGS. 1-3 .

After this etching step is accomplished, the patterned metal layer 65 isconnected between the moveable platform 613 and the fixed frame 611 tobe used as elastic restoring members.

Step S86: Next, a third silicon layer 64 having an accommodation spaceis bonded to the thinned surface 61S2′ of the first silicon layer 61,wherein the accommodation space is to allow the third silicon layer 64not to contact with the moveable platform 613 to maintain the movementfreedom of the moveable platform 613. Accordingly, as shown in FIG. 6 fthe third silicon layer 64 is bonded to the thinned surface 61S2′ withthe fringe region thereof (e.g., the region corresponding to the fixedframe 611). For example, the third silicon layer 64 has walls extendingupward from edges thereof such that the central area is lower than thefringe area. The bonding between the thinned surface 61S2′ of the firstsilicon layer 61 and the third silicon layer 64 is performed usingconventional wafer bonding technology.

Step S87: Next, the second silicon layer 63 is removed to expose themoveable platform 613 and the patterned metal layer 65, as shown in FIG.6 g . For example, the second silicon layer 63 is removed by grinding oretching process to completely remove the second silicon layer 63 orleave a part of second silicon layer 63′ behind which is bonded with thefixed frame 611 according to the MEMS structure and etching process.

Step S88: Finally, the sensor chip 67 to be carried is arranged on thepatterned metal layer 65 to accomplish the sensor package of the presentdisclosure. The sensor chip 67, for example, has solder balls 68 orcontact pads in the bottom surface thereof, and the solder balls 68 arecombined to the patterned metal surface 65 using high temperatureprocess to have good electrical connection.

In addition, if other signal transmission path in addition to thepatterned metal layer 65 is required, at least one bonding wire 19, asshown in FIG. 4 , is formed between the sensor chip 67 and the fixedframe 611 using wire bonding technology. Similarly, before forming thebonding wire 19, contact pads are firstly formed on the moveableplatform 613 and the fixed frame 61 to electrically combine with thebonding wire 19.

In the sensor package manufactured by FIGS. 6 a-6 h , the fixed frame 11includes silicon layers bonded to each other (e.g., first silicon layer61, second silicon layer 63 and third silicon layer 64) but has no oxideinsulating layer therebetween. The second silicon layer 63 and the thirdsilicon layer 64 are respectively disposed at two different sides of thefirst silicon layer 61.

The MEMS actuator of the present disclosure is electrically connected toa circuit board (not shown) by solder so as to electrically connect toother components of the system (e.g., a portable electronic device) fortransmitting signals via traces on the circuit board.

It should be mentioned that although the above embodiments are describedwith one- or two-dimensional linear movement as an example, the presentdisclosure is not limited thereto. In other embodiments, the MEMSactuator triggers the movement or rotation in multiple dimensions byother arrangements of the elastic restoring members.

It should be mentioned that although the above embodiments are describedwith the fixed frame 11 surrounding the moveable platform 13continuously, the present disclosure is not limited thereto. In otherembodiments, the fixed frame 11 is formed corresponding to only two orthree edges of the moveable platform 13, or formed in a discontinuousway surrounding the moveable platform 13 without particular limitationsas long as the moveable platform 13 is moveable with respect to thefixed frame 11.

It should be mentioned that although the above embodiments are describedwith a single sensor package, the present disclosure is not limitedthereto. In the mass production, a plurality of sensor packages of thepresent disclosure are manufactured on a wafer simultaneously, and aplurality of single sensor packages is divided by wafer dicing. Thedicing technology is known to the art and thus details thereof are notdescribed herein.

It should be mentioned that although the above embodiments are describedwith the moveable platform being located in a middle position of theMEMS actuator, the present disclosure is not limited thereto. In otherembodiments, the moveable platform is located at a position instead ofthe central position. In addition, it is possible to arrange more thanone optoelectronic devices on the moveable platform according todifferent applications.

Although the above embodiments show that the sensor package 10 includesmultiple elastic restoring members 15, but the present disclosure is notlimited thereto. In a non-limiting embodiment, the sensor package 10includes one elastic restoring members 15, e.g., as shown in FIG. 9 .That is, in the present disclosure, the sensor package 10 includes atleast one elastic restoring member 15 for providing a restoring forceand a path for transmitting electrical signals.

As mentioned above, the conventional MEMS can be used as an actuator toadjust the exact position. Therefore, the present disclosure provides asensor package having a movable sensor (as shown in FIGS. 1 to 4 ) and amanufacturing method thereof (as shown in FIGS. 7-8 ) that dispose asensor chip on the elastic restoring member to allow the elasticrestoring member to have functions of transmitting signals and providingrestoring force at the same time.

Although the disclosure has been explained in relation to its preferredembodiment, it is not used to limit the disclosure. It is to beunderstood that many other possible modifications and variations can bemade by those skilled in the art without departing from the spirit andscope of the disclosure as hereinafter claimed.

What is claimed is:
 1. A micro-electromechanical system (MEMS) package,comprising: a fixed frame; and a moveable platform, configured to bemoved with respect to the fixed frame along at least one direction andhaving a rectangular shape, wherein the moveable platform comprises aplurality of comb electrodes at two opposite edges of the rectangularshape of the moveable platform; and multiple elastic restoring members,formed between the fixed frame and another two opposite edges, differentfrom the two opposite edges, of the rectangular shape of the moveableplatform, and configured to restore a position of the moved moveableplatform.
 2. The MEMS package as claimed in claim 1, wherein themultiple elastic restoring members are formed by a patterned metallayer.
 3. The MEMS package as claimed in claim 1, wherein the multipleelastic restoring members are formed as straight lines between the fixedframe and the moveable platform.
 4. The MEMS package as claimed in claim1, wherein the multiple elastic restoring members arranged at each ofthe another two opposite edges are all parallel to each other.
 5. TheMEMS package as claimed in claim 1, wherein the fixed frame comprises aplurality of comb electrodes opposite to the plurality of combelectrodes of the moveable platform configured to generate electrostaticforce to move the moveable platform.
 6. The MEMS package as claimed inclaim 1, further comprising an electrical insulation layer formedbetween the moveable platform and the multiple elastic restoringmembers, and between the fixed frame and the multiple elastic restoringmembers.
 7. The MEMS package as claimed in claim 1, further comprising aresidual silicon layer on the fixed frame and outside the multipleelastic restoring members.
 8. A micro-electromechanical system (MEMS)package, comprising: a fixed frame, having a rectangular inner edge; anda moveable platform, configured to be moved with respect to the fixedframe along two directions; and four elastic restoring members,straightly connected between the fixed frame and the moveable platform,and configured to restore a position of the moved moveable platform,wherein one end of each of the four elastic restoring members isarranged at one of four corners of the rectangular inner edge of thefixed frame.
 9. The MEMS package as claimed in claim 8, wherein the fourelastic restoring members are formed by a patterned metal layer.
 10. TheMEMS package as claimed in claim 8, wherein the fixed frame comprisessilicon layers bonded to each other without an oxide insulating layertherebetween.
 11. The MEMS package as claimed in claim 8, wherein thefixed frame has a plurality of first comb electrodes and the moveableplatform has a plurality of second comb electrodes, and the plurality offirst comb electrodes and the plurality of second comb electrodes areconfigured to generate electrostatic force to move the moveableplatform.
 12. The MEMS package as claimed in claim 8, further comprisingan electrical insulation layer formed between the moveable platform andthe four elastic restoring members, and between the fixed frame and thefour elastic restoring members.
 13. The MEMS package as claimed in claim8, further comprising a residual silicon layer on the fixed frame andoutside the four elastic restoring members.
 14. Amicro-electromechanical system (MEMS) package, comprising: a fixedframe; and a moveable platform, configured to be moved with respect tothe fixed frame along at least one direction; and at least one elasticrestoring member, each being formed as a straight line between the fixedframe and the moveable platform, and configured to restore a position ofthe moved moveable platform.
 15. The MEMS package as claimed in claim14, wherein the at least one elastic restoring member is a patternedmetal layer.
 16. The MEMS package as claimed in claim 14, wherein themovable platform has a rectangular shape, and the at least one elasticrestoring member is formed between two opposite sides of the rectangularshape and the fixed frame.
 17. The MEMS package as claimed in claim 14,wherein the movable platform has a rectangular shape, and the at leastone elastic restoring member is formed between four corners of therectangular shape and the fixed frame.
 18. The MEMS package as claimedin claim 14, wherein the fixed frame has a plurality of first combelectrodes and the moveable platform has a plurality of second combelectrodes, and the plurality of first comb electrodes and the pluralityof second comb electrodes are configured to generate electrostatic forceto move the moveable platform.
 19. The MEMS package as claimed in claim14, further comprising an electrical insulation layer formed between themoveable platform and the at least one elastic restoring member, andbetween the fixed frame and the at least one elastic restoring member.20. The MEMS package as claimed in claim 14, further comprising aresidual silicon layer on the fixed frame and outside the elasticrestoring member.